Identification of physical parameters of a synchronous generator from online measurements

A new method to determine physical parameters of a synchronous generator based on an online measurement of the electrical power, terminal voltage, and field voltage, following a small perturbation of the field voltage, and the rotor angle at the same steady-state operating condition is described in this paper. A multivariable linear transfer function, identified using the sampled input-output data, is converted to the parameters of the Heffron-Phillips model. Using the relations of the Heffron-Phillips parameters with the physical parameters, the physical parameters are estimated. These estimated parameters are then used in a non-linear structure to model the synchronous generator. Experimental results with the proposed method applied to a micromachine show good accuracy of the model and also show that the identified nonlinear model is valid at other operating conditions. At dramatically different operating conditions, however, to include the effects of unstructured nonlinearities such as magnetic saturation, the parameters of the nonlinear structure can he slightly adjusted for better performance.